code to put in the single page where you want the sidebar:
<?php
$post = $wp_query->post;
if ( (in_category('80')) {
include(TEMPLATEPATH . '/sidebar80.php');
} elseif ( (in_category('81')) {
include(TEMPLATEPATH . '/sidebar81.php');
} else {
include(TEMPLATEPATH . '/sidebar.php');
}
?>
well this is working for me…